Scarlett Morse sometimes takes a break during running drills at field-hockey practice. The break saves her energy and rests her knees for upcoming games.

The sophomore uses a laptop to take notes in class at Worthington Kilbourne High School to prevent severe pain in her fingers and hands.

But the 16-year-old refuses to take the elevator at school despite the aches caused by Sjogren’s syndrome — an autoimmune disease in which the white blood cells attack moisture-producing glands — and juvenile arthritis.

“I don’t look like I need it,” she said, noting that it’s difficult for most people to understand that a 16-year-old can have arthritis.

Plus, “The biggest key for her is to stay active,” said her dad, Ted.

As the youth honoree for the Jingle Bell Run/Walk for Arthritis put on by the Arthritis Foundation on Saturday, Morse and her 74-person team, including many of her teachers, hope to raise awareness that more than 300,000 American children suffer from debilitating arthritis, many showing little or no outward signs of the disease.

There are more than 100 types of arthritis, said her mother, Michele.

“Most people have that stereotype of an old woman sitting in a wheelchair,” she said. “So many people have told Scarlett, ‘Kids don’t get arthritis.’”

That reaction has made her daughter cry on more than one occasion.

While in seventh grade, lumps — sometimes the size of golf balls — began appearing on Scarlett’s neck and behind her ears. After visiting several health specialists, she was diagnosed with Sjogren’s.

It’s a chronic and progressive disease that mainly affects the salivary glands and glands in the eyes, Michele Morse said. (Tennis player Venus Williams also suffers from it.) It commonly develops in the presence of another autoimmune disease, such as arthritis.

“Her eyes are so dry,” Michele Morse said. “If there is a ceiling fan on at a restaurant, her eyes will get really red.”

Fatigue causes her to nap after most school days, and the immunosuppressant drugs she takes make it easier for her to get sick.

She misses school every two or three months to see a doctor in Pittsburgh. Depending on Scarlett’s pain, the doctor recommends certain medication changes or physical and water therapies.

The hardest part about living with Sjogren’s and arthritis is keeping up with friends, Scarlett said.

“Right now, with the weather, my knees are in a lot of pain; I have more hip pain than usual,” Scarlett said. “It continues until you get to sit down for a while.”

Her family hopes that she will undergo chemotherapy to offer some semblance of a cure, they said, but insurance doesn’t cover treatment.

In the meantime, Scarlett, the fourth of five siblings, and her family have raised about $3,000 this year for the Arthritis Foundation.

Scarlett plans to wear a tutu, tights and festive socks and don crazy hair a la characters from How the Grinch Stole Christmas! for the race.

Although a fun event for her and her family, the race is an important opportunity for Scarlett to share her story.

“I want other people to know that kids have arthritis, too, and, hopefully, we’ll find a cure.”